Jillian loves quilting. At first, she thought that she would love it because it is something that she could do with her grandmother, but now she is sure that she actually really loves the quilting itself. Jillian loves creating something with her hands and seeing the finished project.

Jillian asked her grandmother how long she had been quilting and her grandmother told her that she had been quilting for a long time, long before Jillian was even born. Jillian began to wonder how many other people in the world quilt.

During a trip to the library, Jillian used the computer to do some research. She found that the number of people quilting in the United States has increased significantly from 2006 to 2009. Quilters.com completed a survey and here are their results.

In 2006, 21.3 million people were quilting. That means that about 13% of all Americans were making quilts.

In 2009, 27 million people were quilting. That means that about 17% of all Americans were quilting.

That is an increase of 4% in just three years! It might not seem like much, but it is a significant increase!

Jillian wants to show her grandmother the results of the survey. She has decided to create a picture of the data to show how the information has changed. To do this, she is going to create a circle graph.

She will create two circle graphs, one for 2006 and one for 2009.

Do you know how to do this? During this Concept you will continue learning about circles. At the end of the Concept, you will see how Jillian used a circle to display the quilting data.

Guidance

In our opening problem, Jillian wants to display her quilting data in a circle graph. We can use circle graphs to display real-world data. In fact, we do it all the time.

What is a circle graph?

A circle graph is a visual way to display data using circles and parts of a circle.

A circle graph uses a circle to indicate 100%. The entire circle represents 100% and each section of a circle represents some part out of 100.

You can see here that this circle graph is divided into five sections. Each section represents a part of a whole.

Back in an earlier Concept, we looked at the spending habits of a teenager. Here you can see that 50% of his money went into savings. 40% of his money was spent on food and that 10% of his money went to baseball cards.

Use this circle graph to answer the following questions.

Example A

What is the most popular music selection?

Solution: Pop music

Example B

What percent of the students chose pop music?

Solution: 50%

Example C

What percent of the students chose rock music?

Solution: 25%

When Jillian creates her circle graphs, she will be able to create ones that show how quilting has grown from 2006 to 2009. Let’s go and revisit that introductory problem now.

Here is the original problem once again. Reread it and underline any important information.

Jillian loves quilting. At first, she thought that she would love it because it is something that she could do with her grandmother, but now she is sure that she actually really loves the quilting itself. Jillian loves creating something with her hands and seeing the finished project.

Jillian asked her grandmother how long she had been quilting and her grandmother told her that she had been quilting for a long time, long before Jillian was even born. Jillian began to wonder how many other people in the world quilt.

During a trip to the library, Jillian used the computer to do some research. She found that the number of people
quilting in the United States has increased significantly from 2006 to 2009.
Quilters.com completed a survey and here are their results.

In 2006, 21.3 million people were quilting. That means that about 13% of all Americans were making quilts.

In 2009, 27 million people were quilting. That means that about 17% of all Americans were quilting.

That is an increase of 4% in just three years! It might not seem like much, but it is a significant increase!

Jillian wants to show her grandmother the results of the survey. She has decided to create a picture of the data to show how the information has changed. To do this, she is going to create a circle graph.

She will create two circle graphs, one for 2006 and one for 2009.

Let’s look at Jillian’s data.

The first circle graph will show that 13% out of 100% of people were quilting in 2006. Here is the circle graph.

The second circle graph shows that in 2009, the number of people quilting increased to 17% out of 100%.

Now Jillian has two circle graphs that she can share with her grandmother.

Vocabulary

Here are the vocabulary words in this Concept.

Area

the surface or space of the figure inside the perimeter.

Radius

the measure of the distance halfway across a circle.

Diameter

the measure of the distance across a circle

Squaring

uses the exponent 2 to show that a number is being multiplied by itself.